With the development of the mobile communication technology, advanced cellular networks, such as networks based on LTE standard (Long Term Evolution, a standard used by some fourth generation (4G) networks), are being deployed all over the world. Because of the introduction of key technologies including OFDM (Orthogonal Frequency Division Multiplexing) and MIMO (Multi-Input & Multi-Output), the LTE standard can be used to significantly increase spectral efficiency and data transfer rates.
On the other hand, simultaneously with the increase of network rate and frequency band utilization ratio, the appearance of multi-mode terminal (terminals with two subscriber identity modules, such as dual-card dual-link terminals) enables users to establish data service links while standby for voice services.
However, the current multi-mode terminal can only achieve that one of the subscriber identity modules (SIM) uses a 4G (e.g., LTE) network and its data services, and the other identity module can only use the third generation or second generation (3G/2G) services.
Therefore, the current terminal often cannot support both of two subscriber identity modules using LTE networks simultaneously, which affects the user experience. The current technology has defects and needs to be improved.